A) \[4\]
B) \[3\]
C) \[\sqrt{12}\]
D) \[\frac{7}{2}\]
Correct Answer: A
Solution :
We have, \[{{a}^{2}}=16\] and \[9={{b}^{2}}={{a}^{2}}(1-{{e}^{2}})\] \[\Rightarrow \] \[9=16(1-{{e}^{2}})\] \[\therefore \] \[e=\frac{\sqrt{7}}{4}\] Thus, the foci are\[(\pm \sqrt{7},\,\,0)\]. The radius of required circle \[=\sqrt{{{(\sqrt{7}-0)}^{2}}+{{3}^{2}}}\] \[=\sqrt{7+9}\] \[=4\]You need to login to perform this action.
You will be redirected in
3 sec